1. Field of the Invention
The present invention relates generally to endodontic files and more particular to root canal files or reamers used in the cleaning of material present in the root canal of human teeth and for enlarging and shaping the root canal so that it is prepared for receiving filling material.
2. Description of the Related Art
A great improvement in the dental profession in the last half century has been in the field of endodontics, that is, the treatment of abscessed teeth by treatment of the tooth root canal. A relatively, but yet difficult dental procedure is that of cleaning, shaping and filling the root canal of a patient's tooth. In the performance of the root canal procedure typically a hole is first drilled in the crown or the exposed portion of the tooth. The hole drilled through the crown provided access to the interior of the tooth and specifically access to the tooth root canal or root canals. In order to treat the tooth, the canal or canals must be thoroughly cleaned of pulpal material that, in the case of an abscessed tooth, is typically infected. The technician or dental practitioner must remove this pulpal material to alleviate the infection. Next the technician or dental practitioner must clean and shape the root canal so that it can be effectively filled with a filler material, such as gutta percha.
Much work has been done on the instrumentation need for effective treatment of root canals. Root canals are typically treated with endodontic files. The term “file” as used in this patent application means an elongated device insertable into a root canal and that can be manipulated either manually or by machine, to clean and shape the root canal. Thus a dental file serves two basic purposes. First it serves to remove pulpal material from the interior of the tooth. Second it serves to shape the tooth root canal so that it can be more effectively filled. Thus, in addition to the cleaning function, a typical dental file serves also as a reamer, that is, a device to enlarge and shape the canal. In this application, the term “file” is intended to mean a “reamer/file” since it functions not only to clean a root canal of pulpal material but also to shape or ream the root canal.
For background information relating to endodontic files of the type that is the subject of this patent application, reference may be had to the following issued United States patents and publications:
U.S. Pat. No.INVENTOR(S)ISSUE DATETITLE4,443,193RoaneApr. 17, 1984Endodontic Instrument4,536,159RoaneAug. 20, 1985Endodontic Instrument4,934,934Arpaio, Jr. et al.Jun. 19, 1990Dental File/Reamer Instrument5,380,200Heath et al.Jan. 10, 1995Endodontic Instrument Of PredeterminedFlexibility5,464,362Heath et al.Nov. 7, 1995Endodontic Instrument5,503,554SchoeffelApr. 2, 1196Endodontic Files5,658,145Maillefer et al.Aug. 19, 1997Set Of Instruments For Boring DentalRadicular Canals And Method Therefor5,676,541Maillefer et al.Oct. 14, 1997Set of Instruments Of Increasing DimensionFor The Boring Of Radicular Dental Canals5,692,902AebyDec. 2, 1997Set Of Instruments For The Boring OfRadicular Dental Canals5,873,719Calas et al.Feb. 23, 1999Dental Reamer5,897,316BuchananApr. 27, 1999Endodontic Treatment System5,921,775BuchananJul. 13, 1999Endodontic Treatment System5,975,899Badoz et al.Nov. 2, 1999Dental Reamer6,012,921RiitanoJan. 11, 2000Endodontic Systems For The Anatomical,Sectional And Progressive Corono-ApicalPreparation Of Root Canals With Three SetsOf Dedicated Instruments6,074,209JohnsonJun. 13, 2000Reduced Torque Endodontic File6,217,335Riitano et al.Apr. 17, 2001Endodontic Systems And Methods For TheAnatomicall, Sectional And ProgressiveCorono-Apical Preparation Of Root CanalsWith Minimal Apical Intrusion6,267,592MaysJul. 31, 2001Highly Flexible Instrument For DentalApplications6,312,261MaysNov. 6, 2001Endodontic Obturator With RemovableCarrier And Method Of Use Thereof6,315,558Farzin-Nia et al.Nov. 13, 2001Method Of Manufacturing SuperelasticEndodontic Files And Files Made Therefrom6,390,819RiitanoMay 21, 2002Endodontic Systems And Methods For TheAnatomical, Sectional And ProgressiveCorono-Apical Preparation Of Root CanalsWith Dedicated Stainless Steel InstrumentsAnd Dedicated Nickel/Titanium Instruments6,419,488McSpadden et al.Jul. 16, 2002Endodontic Instrument Having A Chisel Tip6,514,076Bleiweiss et al.Feb. 4, 2003Precipitation Hardenable Stainless SteelEndodontic Instruments And Methods ForManufacturing And Using The Instruments6,520,774MaysFeb. 18, 2003Highly Flexible Instrument For MedicalApplications6,644,972MaysNov. 11, 2003Endodontic Obturator With RemovableCarrier And Method Of Use Thereof6,746,245Riitano et al.Jun. 8, 2004Methods For Cleaning And ShapingAsymmetrical Root Canals In An AnatomicalFashion2004/0121283MasonJun. 24, 2004Precision Cast Dental Instrument2003/0077553BrockApr. 24, 2003Endodontic Instrument Having NotchedCutting Surfaces2004/0058297DangerMar. 2, 2004Root Canal Instrument2004/0043357GarmanMar. 4, 2004Endodontic Instrument2004/0023186McSpaddenFeb. 5, 2004Multi-Tapered Endodontic FileRe. 34,439HeathNov. 9, 1993Dental Compactor Instrument